This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objective: To determine noninvasively the effects of aging and reduced caloric intake on the physiological measures of sensitivity to sound stimuli. Caloric restriction (CR) is the only known method for increasing lifespan of laboratory animals. Caloric restriction (CR) slows aging in many species and protects some animals from age-related hearing loss (ARHL), but the effect on humans is not yet known. This study was conducted in conjunction with our larger investigation of CR in rhesus monkeys and a publication has resulted this year. Because rhesus monkeys in the CR study have a maximum longevity of 40 years, the full benefits of CR may not yet be realized. This research used WNPRC Animal Services and Aging Resources. PUBLICATIONS: Fowler CG, Chiasson KB, Leslie TH, Thomas D, Beasley TM, Kemnitz JW, Weindruch R. Auditory function in rhesus monkeys: Effects of aging and caloric restriction in the Wisconsin monkeys five years later. Hear Res. 2010 Jan 15. [Epub ahead of print]